Nail and powered nailer

ABSTRACT

A nail and nail clip arrangement in which so-called common nails may have their shanks grit-blasted and the edge of their heads flattened along equal parallel planes to provide a minor diametral dimension of the nail head that is approximately twice the diameter of the nail shank. The heads are alternately offset laterally in contact with each other in two rows and with the heads of the two rows alternately cross-engaging and the shanks of the nails interdigitate at an acute angle adjacent their points. The end nail at the feed end of one row extends beyond the next adjacent nail of the other row far enough for a powered driver to nip off and drive the lead nail upon actuation of the power mechanism.

United States Patent Schrepferman 1 Sept. 30, 1975 [54] NAIL AND POWEREDNAILER 3.437.249 4/1969 Baum 227/120 3,504,840 4/l970 Wandel et al227/120 X Inventor: John R. Schrepferman, Merriam,

Kans' Primary E.\'aminerGranville Y. Custer, Jr. [73] Assignee: Bliss &Laughlin Ind., lnc., Oak Attorney, Agent, or FirmWats0n D. l-larbaughBrook, Ill.

22 Filed: on. 11, 1974 [571 ABSTRACT A nail and nail clip arrangement inwhich so-called [2]] Appl 514328 common nails may have their shanksgrit-blasted and R l t d US, A li ti D t the edge of their headsflattened along equal parallel [62] Division of Scr N0 3% 243 Apr 18 973planes to provide a minor diametral dimension of the v l l nail headthat is approximately twice the diameter of [57] U S Cl 0 227/130.227/120 the nail shank. The heads are alternately offset later- 1 BZSCU04 ally in contact with each other in two rows and with 58 Field ofSearch 227/ 126 heads of the two rows alternately cross-engaging 277/1276 and the shanks of the nails interdigitate at an acute angle adjacenttheir points. The end nail at the feed [56] References Cited end of onerow extends beyond the next adjacent nail of the other row far enoughfor a powered driver to UNITED STATES PATENTS nip off and drive the leadnail upon actuation of the 3.081466 4/1963 Tobias 1 227 x powermechanism 1099 837 8/1963 Hellman et al. 227/130 X 3.157.884 ll/l964Dccof ct al. 227/136 5 Claims, 29 Drawing Figures 64 24 52 H 32 I l J iso I l 42 56 I 54 22U 46 I 60 x 20 22 66 40 68 I 26 I lL 7o i l 96 I I I98 US, atent Sept. 30,1975 Sheet 1 of5 9 US, Patent Sept. 30,1975 Sheet3 of5 3,908,884

US. Patfint Sept. 30,1975 Sheet 4 of5 3,908,884

21mm Sept. 30,1975 Sheet 5 of 5 NAIL AND POWERED NAILER BACKGROUND OFTHE INVENTION spaced, or are disposed edge-to-edge in a transport train,or are axially offset enough to overlap vertically with the head of thelead nail contacting the adjacent shank on the next nail head above it.In most cases, however, unless supported in an inclined clip member thenails are carried on a feed tape means or a frangible adhesive thatsupports the nails as a stick unit.

In feeding a train of nail heads in edge-to-edge contact by a resilientforce under working conditions, the contacting edges of the heads canbecome overlapped and cause malfunctions because there is only acritical single point of contact between adjacent nail whose naail headedges are rounded in two directions. In feeding overlapping heads thereare theoretically two contact points, but they are critically andcontiguously arranged at one end of the nails.

The feeding can be done by gravity, if the nails are loose, or bymechanical means engaging the nail heads and shanks at the level of thecontact points to provide clip-forming supports such as adhesive tape orfrangible mastics, etc. Moreover, a lot of available clip storage spacefor nails is not utilized because of the wide spaces between the nailshanks. The spacing is at least the radial distance of the headoverhanging the shank.

Where a supporting means for spaced shanks is used, waste material hasto be disposed of as the lead nail is stripped free each time fordriving, and, although heads have been provided having the same width asthe nail shank, the holding power of the reduced head area is greatlyreduced to a fraction of what may be desired of a common nail having ashank of the rated diameter involved.

SUMMARY OF INVENTION In the present invention, the nail emboyding theinvention is characterized by having a flat head that is edge flattenedalong equal parallel lines spaced a distance twice the diameter of thenail shank. Such nails not only serve as a standard nail in conventionalways with conventional equipment but further fosters a shape and cliparrangement for power nailers in which utmost space economy is attainedin a clip of large head area nails. The shanks are contiguous and theheads are arranged alternately contiguous for extensive contactengagement and the nails contact at opposite ends for clip stability.The nails can be fed by hand, by gravity or by spring. Also, the nailsare easily handled because they will not roll on a flat surface and canbe collated in either one of two orientations by flat edge portions onradially opposite sides of the rim of the head.

The flat edge portions are radially spaced in each nail a distance twicethe diameter of the nail shank so that the shanks of two rectilinealrows of nail heads contact at points adjacent to their pointed ends, andalternate heads contact at the nail head ends whereby clip stability isimproved by each intermediate nail engaging two nails on each side. Eachend nail of a clip extends at its head beyond the next adjacent nail farenough to be nipped from the nail assembly by the powered driverregardless of which side the head is on of the double row of centrallyinterdigitating transversely contiguous heads.

Moreover, in the feeding of nails progressively into the driver strikingposition the driver of the power unit can serve as a feed stop in a lowretracted resting position during idle conditions, or, if the driver israised to a poised resting position above the head of the lead nail afeed stop is preferably employed on each side of the path of the driverbelow the end of the driver to locate the nail in its drive position.The driver then operates to nip or strip and drive the lead nail. Whenstruck by the driver the head and shank of the nail are both cammed intosubstantial alignment with the driver. The head is cammed by a fixed camand the nail point is cammed by a resilient finger or fingers at thefeed end of the clip, the fingers yielding to the downward passage ofthe nail head, yet clearing the driver so that it can strike the nailwith one blow or transmit plural blows if the driver is repeatedlystruck by a repeating hammer.

Where nails are fed pneumatically by a tube each nail head on its drivenmovement preferably passes through a throat cross-sectionally shaped tomate with the shape of the nail head which helically turns the nailshank during its initial penetration of the nailed material for easingthe penetration without damage to the workpiece or to the holdingstrength of the nail. If the nail is a threaded nail, the helical leadstarts the threading rotation with a thread lead equalling that of thenail, preferably, approximately 65.

The nails also are particularly easy to collate into compact strips.Although this can be accomplished with two moving converging lines ofnails, with the heads oriented flat-to-fiat and the shanks depending, itis preferred to utilize a single line of nails arranged with the flatedges aligned in parallel planes. The line is advanced lengthwise to astation where the lead nails are pushed laterally in pairs to form adouble row with head edges fiat-to-flat and the shanks are positivelydisplaced to interdigitate. Thereupon the next step can be either toapply a quick drying frangible mastic to the contact lines of the headsand the interdigitating shanks, or, the assembly with or without anymastic securement of the nails, can be fed into a V-shaped sheet metalclip that centers the nail points and carries the weight of nails alongtwo outside facing channels that engage the outside edge portions of thecontacting heads.

Preferably, for ease in using the clip, the clip is longitudinally openalong the top and an L-shaped spring drawn pusher carried by the powerunit is manually drawn out the length of the clip and lodged against thehead of the outermost end nail to feed the nails towards the drivestation.

Objects of the invention are to provide an improved common or threadednail which lends itself to economical packaging and use in powernailers; which enables a power controlled twisting of the nail as itenters the workpiece, or, as it comes to rest in the workpiece; whosehead can interlock with the workpiece when deeply set; and which is easyto collate compactly in a nail feed or shipping package.

A further object is to provide a nail shape that is easy to form andreadily identified in place as to source and physical characteristicsincluding the size of the shank embedded in a workpiece.

The invention also contemplates an improved collating apparatus andprocess for compactly packaging common nails in a storable feed unit forpower nailers.

Another object of the invention is to provide a flat FIG. 25 is aperspective view similar to FIG. 23 showing a threaded nail with agrit-blasted shank;

FIG. 26 is a side elevation of a stick of nails in which the nails areheld together by frangible mastic;

h d d il f approximately a 12 gauge size that has FIGS. 27 and 28 aretop and bottom views taken on over a third greater holding strength of acomparable lines 27-27 and 2828 respectively in FIG. 26; shaped 11 gaugenail bright. FIG. 29 is a perspective view of a clip end cap carry-Other and further objects and advantages will appear ing a nail shankspacing rod. from the following description and claims relating to thedrawing in which:

FIG. 1 is a side elevation of a nail gun embodying and NAIL utilizingthe invention;

FIGS 2 and 3 are sectional views taken on lines Referring to thedrawings, the nails 10 illustrating the and 3 3 respectively ininvention can be classified as common, flat-headed 12 FIG 4 is anenlarged perspective View of a portion of gauge tempered wire nailshaving the usual dimensions the Sectional View of FIG. for makingpallets. The have flat heads 12 and shanks FIG. 5 is an enlargedsectional view taken on line numerals without a Suffix are used,geflericauy 55 of FIG. 3 with the working parts poised for opera- Wh'iesuffixes r (F 23) or t (FIG' 25) mdlcate the tion; round or threadedcharacter of the shanks, respec- FIG. 6 is a view like FIG. 5 showingthe working parts tiveiym 7 P sf nall'dn ven poslltloni f The rateddiameter D of the heads 12 are substanls i lagramrpanc Op p an 0aFOIWen' tially more than twice the diameter d of the shanks 18 tionalcollating drum in WhlCh the collated nails move thus D 2d Furthermorethe heads are flattened radially from the collation discharge opening; hd t 16 l n l 1 FIG. 8 is an enlarged top plan view partly in section eges as a a ong equ.a e p .anes or of the formation of collated nailsinto clips for use with hnes Spaced fflf a distance that IS twice thedlameter the gun; d of the shanks, thus fF2d for reasons later ex- FIGS.9, l0 and 11 are schematic illustrations of the plamed' v v steps takenforming a double line of interdigitated nails Preferably, the flatteningat 16 is accomplished by from a Single line: orientanqni radiallydirected compression or swaging dies which i a diagrammatic Vemcal ethrough work the metal, increase the axial width of the resulting theoscillating and reciprocating mechanism shown in faces 16 and therebyprovides flat Surfaces that engage FIGS 9, i and 11; one another asbetween collated nails in a stabilizing 1S ahenlarged sectional Viewtaken on lme relationship by substantial engaging surfaces which 1313 inF 8; permit appreciable relative movement without overlap- FIG. 14 1s aclose-up perspective, partly in section II- ping when being collated andStored e loosely lustrating the nose portion of the gun for feeding andi driving nails from a clip; Also, preferably, the shanks, whetherthreaded or FIG. 15 is a sectional vie a e On line 15-15 0f not, aregrit-blasted as indicated at GB with size 80 alu- FIG. 14; minum oxidegrit to remove the bright surface of the FIG. 16 IS a sectional viewsimilar to FIG. 15 showing nail and provide small pits 21 with minutesharplythe cooperating locations of the nails and driven for h d 11 Thii i l l true ith tempered nipping and driving a lead nail a time; nailshanks. With this inexpensive treatment 2 inches of FIG. 17 is avertical sectional view taken on line h h k f 65 th d d 12 gauge il htreated l of 16 0f the driving barrel with the lead provides a holdingstrength against withdrawal that is nail pp and being guided into fulldrive Position? substantially greater than a like nail shanksand-blasted 18 is a Perspective View of a threaded nail head with thesame size conventional sand particles. Such is rotation being driveninto a wooden workpiece; also much greater than a conventional 11 gaugenail FIG. 19 is a perspective view similar to FIG. 18 showand muchgreater thanwith any 12 or 11 gauge coated ihg the nail head recessedand ihiei'ioekihg with the nail tested. The harder the grit and thesmaller the grain wood fiber s; size above 40, namely, 70 to 90, 80 isoptimum, the

20 15 a Section taken on line 2020 of 19; greater the holding power ofthe nail and the more im- 21 is a P pe end w the h feed P portant becomethe advantages that it is capable of colas related to the nails and theresil ent nail feeder; iation i a di i li i h h expense, neces- 22 anenlarged sectional View through the l? sity or waste of coatings andadhering material on the and the gun support magazine for the clip; h k

FIG. 23 is a dimensioned perspective view of a nail embodying theinvention whose shank is grit-blasted; By way of example, with respectto helically threaded FIG. 24 is an enlarged sectional view taken online pallet nails actual exploratory holding strength tests 24-24 ofFIG. 23 illustrating the surface derived from have shown the followingresults with nails identified as grit-blasting; follows:

ide ii t i ii- Length Wire li y Head Leglgth Num- Thread withdrawal loadcation diameter outside diameter diamond iff angle Mini- Maxi-Averdiameter point flutes mum mum age In. In. In. In. In. Degrees Lb.Lb.

2 l/2Xll 2 |7/32 0.121 0.133 9/32 5 32 4' 64 290 340 315 No coatContinued Nail Threaded Length Withdrawal load identifi- Length Wirebody Head of Num- Thread ber cation diameter outside diameter diamond ofangle Mini- Maxi- Averdiameter point flutes mum mum age In. In. In. In.In. Degrees Lb. Lb.

2 112x11 2-1/2 .121 .127 9/32 5/32 5 65 305 340 320 TN25 No coat 2l/2Xl2 2-9/16 .106 .119 l/4 l/8 4 63 325 410 355 25 T No coat Sand 2 1/212 217/32 .105 .123 1/4 1/8 4 63 270 360 330 25 Coated 2 l/2Xl2 2-9/16.105 .124 H4 H8 5 67 355 465 390 25 Grit Tentative conclusions:

1. 2 /2 inches X 12 nails have greater holding strength (HS) than 2 /2inches X 11 nails.

2. 2 /2 inches X 12 nails, not coated, have holding strength greaterthan coated nails.

3. 2V2 inches X 12 grit-blasted nails (size 80 grit) have the greatestholding strength.

4. The minimum HS of grit-blasted shanks is approxi mately equal tomaximum I-IS of coated nail.

Moreover, during withdrawal it was noticed that the high holdingstrength persists, and renailing in the same nail hole retainsapproximately the same high holding strength.

In some respects I am not able to account fully for these improved andunexpected results which are obtained by the invention described, and itshould be understood that any attempt to analyze the theory which isbelieved to be responsible for these results is to be construed not asdefining a mode of operation, but merely as a possible explanation ofcertain physical phenomena which have been observed.

Wood fiber displacement is involved in both axial directions of nailmovement and, if not split, reamed or torn, their resiliency has maximumresistance up to the point just before splitting occurs. Under theseconditions they provide a firm reaction which can be referred to as aheavy clamping frictional contact that is maintained substantially highand constant. Also, the wood fibers at any transversely severed ends canbe bent, displaced or end compacted at the nail interface without atearing action as part of the clamping action.

It also appears that sand-blasting or grit-blasting with large size gritflattens or slicks the nail shank surface, particularly if the metal isuntempered, whereas the small hard grit pits the surface, which thesmall size sand does not, with many minute upstanding edges that augmentthe friction without tearing the wood fibers, going in or coming out,particularly with a 12 gauge size nail which is of a size that does notsplit the wood fibers.

Fixed protrusions provided sometimes on axially driven wood nail shanksoperate to oversize or ream the wood fibers at the interface. Thisconstitutes damage to the wood fibers, and very little frictionalengagement remains. Moreover, the fibers broken in one direction willyield more readily in the other direction and once withdrawal begins,even slightly, any holding strength drops rapidly. Renailing in whole orin part in the same hole under these conditions entails a falseexpectancy of reestablishingthe original holding strength.

NAIL GUN, Shape In driving the nail GB embodying the invention it may benoted that a heavier driving force proportional to the nails increasedholding strength is required.

Preferably, for high speed nailing, the nails are pneumatically fedsingly by tube directly from storage, otherwise either from a collatoror clip, to the driving com partment 101 (FIG. 3) ofa pneumatic gun 15(FIG. 1).

Also, in absence of special applications it is highly desirable that anail 10 of the invention, rated as a common nail, be disposed axially inits driving direction 13 (FIG. 23), and be advanced laterally in adirection 17 (FIGS. 23 and oriented normal to the axis of movement 13 ofthe nail so that a magazine 19 (FIG. 4) can be arranged to provide asupport squaring the drive direction normal to the nailing surface.Furthermore, the magazine itself should be narrow enough that the guncan be inclined laterally to the vertical to toe-nail in narrow spaces.This is distinguished from conventional nailers handling loose commonnails or nails fed by magazine in an inclined direction which requireauxiliary attachments, or fed from reel housings that are too widehorizontally to permit inclining the gun to toe-nail with common nails.

Accordingly, as noted in FIG. 1, the magazine is at a right angle to thepower drive housing 26, the lower edge permits lateral' leaning fortoe-nailing, and the nailer is compacted also vertically for a lowhandle that is manipulated quite easily.

NAIL GUN CONSTRUCTION As already noted the nails embodying the inventionillustrated in FIG. 23 comprise a construction in which their flat heads12 have two flat edges 16 of equal length defining for each nail 10 twoparallel planes 16 of substantial area-of-contact on opposite sides ofthe shank 18 and spaced apart a distance equal to twice the diameter ofthe nail shanks (f 2d).

Briefly, the versatility of the present invention for nailing isillustrated with a pneumatic gun 11 shown generally in FIGS. 1-6 havinga piston 20 and cylinder arrangement 22 received in the front portion ofa body housing 26 for relative vertical movement in reciprocating adriver 28. A liner 30, castellated or apertured, around its upper end 24to provide ports 32, is mounted in the housing for durability and easeof manufacturing, and the housing 26 is radially enlarged therearound toprovide a large flow passage 34 for the ports 32. Part way down itslength the liner 30 is provided with a reduced diameter as at shoulder36, and ports 38 are provided therethrough by which the periphery of theupper cylinder 22 is connected to a valve through passage 40 foralternately venting and applying pressure thereto.

The piston is reciprocably mounted in the cylinder 22 and has an axiallypredetermined thin head portion 42 at the top received in the largerupper cylinder portion 22U where it marginally closes the castellateports 32 in its uppermost position as limited by a cylinder head 34removably bolted thereon and carrying a resilient bumper 36 which servesalso as a sealing means for the housing and the piston. The remainingmajor length of the piston is reduced in size as at 44 to slide in thereduced lower cylinder portion 22L in sealing relationship below theshoulder 37. The shoulder provides an offset to define with the overhangof the head portion 42 a secondary cylinder 46 to power the returnstroke of the piston. Thus the cylinders and pistons for the work andreturn strokes compactly overlap and thereby minimize the overall heightof the gun.

A recess 48 in the piston head 42 had access to a passage 50 leadingthrough the cylinder head 34 to a high flow capacity spool valve 52 tocontrol fluid pressure that initiates downward movement of the piston.An appreciable downward movement of the piston would nip the lead nailand open the ports 32 rapidly for a full thrust of the piston withoutany waste of power occurring with any parts first moving in an oppositedirection. All air pressure is effective in a downward direction againstthe piston with all spaces below the piston head 42 vented toatmosphere.

Air pressure is taken from a large collection chamber 54 in the handle56 supplied by an air hose 57 and is controlled by the spool valve 52which handles large volumes of air under pressure quickly through alarge flow area 60 located between the spool valve heads S and L thatare vented to atmosphere at opposite ends. The valve may be fingeractuated by trigger 62 with minimal effort since a slight pressuredifferential on the heads that is provided by relative diameters of thespool heads S and L establishes a continuous differential force normallyurging the valve to a closed position. For this purpose the valve has asleeve liner 64 for the spool valve which is open to atmosphere at itsupper end and provides a step up size at the lower end to a diameter at66 that provides a larger diameter cylinder portion 68 and valve head Lwhereby air pressure which is continuous in the piston chamber 60between the differential valve heads S and L continuously urges thelarger area valve piston L downwardly to a closed position.

In its closed position shown in FIG. 6, pressure from the handle chamber54 enters through passage 70 and passes through the valve chamber 60,through passage 40 and through openings 38 into cylinder 46 to hold thedrive piston 20 in its poised or retracted position with minimum use ofcompressed air volume. When triggered against the mild valve closingpressure (FIG. 6), the lower head L is moved upwardly to vent the returnchamber 46 through openings 38 and passage 40 while the spool chamber 60advances to interconnect the passages 72 and 50 to apply drivingpressure to the space 48 while the upper head S closes the vent passage76 from the space 34. The piston is driven downwardly. Then when thetrigger 62 is released, the pressure present in the spool chamber 60dominates the valve by acting against the larger spool head L exposed toatmosphere on the other side and drives the spool valve downwardlyventing the drive chamber 22 to atmosphere through the port 78 and thelaterally extending exhaust passage 76 for a controlled return of thepiston to its poised position against bumper 36.

Preferably, as viewed in FIG. 1, for the sake of gun compactness, thecloseness of the operators hand to the axis of the nail driver and tothe nailing surface for improved manipulation of the gun it will beobserved the spool valve thereby forms part of the handle, or is presentin the handle.

The piston 20 is lightly but ruggedly constructed to reduce its inertiaand rely essentially upon the air pressure to drive the nails. Thedriver is the rod 28, has a shoulder flange 83 that extends through aspider 84, and is terminally threaded for nut 85 or welded to the spiderto transmit the driving force of air pressure on the piston through thespider to the head of a nail. A spider 88 centers and guides theintermediate portion 86 of the driver 28 with respect to the smallercylindrical surface 22L. Grooves 90 and 92 are provided around the headand spider 84 to receive suitable O- ring seals 94 lubricated bylubricant conventionally supplied to the air pressure supply line.

The depth to which a nail is driven is adjustably determined by aresilient bumper 96 adjustably supported at the lower end of the powercylinder as at 98 by a threaded relationship of the spider 88 at 100.

In operation, the driver 28 on the initial movement of the piston on itsdriving stroke nips the lead nail (FIGS. 16 and 17) to move it towardsits drive position and by this movement the ports 72 and 32 are openedfor a strong, quick and full driving thrust with the compressed airentering through all driving ports 32 while the air present in theperipheral cylinder space 44 below the piston head is vented toatmosphere. Thereafter the piston is returned to its starting positionupon release of the valve by air pressure being admitted to thedifferential area 46 under the piston head 42 while air pressure isvented from above the piston through the exhaust 76. This isaccomplished without undue bounce of the gun in the hand of the operatoras the piston closes the ports 32 and contacts the combination head sealand bumper 36.

NAIL DRIVING In the driving compartment or barrel 101 (FIG. 17) thedriver 28 attached to the piston 26 travels a predetermined axial path.On the opposite sides of this path nail head engaging stops 102 areprovided on the wall of the barrel against which the exposed flatportion 16 of the head 12 of the lead nail 10a of a lateral feed clip 21is contacted at a point where the driver overhangs a substantial portionof the head without touching the secondmost nail head 10b. The stops 102(FIG. 15) are contoured as at 104 to follow the round portion of thenail heads 12 laterally of the axial path of the driver. Below theinitial contact level at 106, the contours 104 are arranged to defineconverging carn chutes 105 that alternately move the lead nail heads toa position coaxial with the driver within the distance of approximatelythree diameters of the nail head. This is done with an initial rapidradial displacement which occurs at the initial slower movement of theaccelerating driver 28. The nail pointsarealso cammed inwardly at 108 topass through centering spring fingers 110 that accept the head of thenail as it is driven from the driving barrel.

Where the nails 10 are supplied one-by-one by a pneumatic tube (notshown) the nails are delivered endwise to the driving chamber throughthe same end receiving the driver. As each nail settles into place inthe chamber, its head rotatively orients itself to the contour thereofthat mates with the shape of the head. Thereafter as the nail is movedthrough the barrel the nail is rotated by the mating contour that isspiralled at an angle of 65 corresponding with the lead of a threadednail lt. Thus whether threaded or not the nail enters the wood with aturning action that assists in avoiding a splitting of the wood fibersso that the greatest possible holding strength is provided for bothsmooth and threaded nail shanks.

It is to be noted (FIGS. 19 and 20) that when threaded nails 102embodying the invention are dispensed and the heads are counter sunkinto the wood fibers 112 of a workpiece 111, the head 12 will take atwist in the wood fibers 112 below the surface 114 thereof and provide alocking relation as at 116 with wood fibers located between it and thesurface through which it was driven. This provides a desirable keyingaction.

Any frangible adhesive that may be used on the heads to secure thecollated nails together as a stick will be sufficiently shattered by thedriver that the remains will easily fall out of the barrel for a cleandrive that establishes great holding strength.

NAIL COLLATION For purposes of rapidly collating the nails for gun use aconventional rotating hopper 122 is provided rotated an axis inclined tothe vertical. The nails are dropped in a trough having a slot in thebottom where the shanks of nails drop through to be supported by theirheads and move outwardly on parallel rail channel members 124 definingtracks 126. The tracks are subject to vibration longitudinally and areslightly inclined for the nails to slide away from the drum. As thenails enter the tracks, they slide below flanges 125 overhanging thenail heads to hold the heads marginally in a fixed plane and provideconvergence of the sides 128 to contact the edges of the nail headsloosely. Adjacent the hopper the sides 128 are spaced the distance D andconverge to the distanceff(FIG. 8). One of the sides 128A isindependently mounted as a slider by headed pins 127 in slots 129 andoscillated longitudinally against spring 121 by a lever 131 pivoted at133 engaging the slider 128A at one end and actuated at the other end bya roller 135 engaged by gear teeth 137 on wheel 139. The slider 128A hasa counter current shoulder 123 that engages the advancing nail heads attheir major dimension to agitate and turn them until they turn enoughfor the flat edges 16 to pass between the converged side guides todispose the flat edges in alignment and carry them in that alignment toa collection station where an advancing means 136 is provided to movethe nails laterally two-by-two into a final collation assembly line. Forthis purpose, as illustrated in FIG. 12, each successive pair ofadjacent nails are engaged by followers 136 driven by cams 138 on thewheel 139. Follower 1361-1 has offset shoulders spaced the distance d ofthe nail shank diameter that engage the flat edges 16 to offset themthat distance and push them into the clip form shown in FIG. 13. Thefollower 136$ is synchronized by the cams 138I-I and 1388 as shown inFIGS. 9, 10 and 11 to engage the shanks of each pair of nails after theyare offset and has a V- shape 141 to bring the points of the nails intooverlapping interdigitating relation at the nail points.

Thus the collation provides shank and head contacts for each nail whichare offset horizontally whereby the lead nail of the pair is pushed offahead of the companion nail a distance equal to d with a stroke distanceof at least 2d. As so moved, the points of the shanks are cammed by aV-form 141 to overlap in contact with each other in interdigitatingrelation in the final assembly.

In this relation, the nails move along either to receive a frangiblemastic adhesive covering the overlapping inner portions of the heads(not shown) or the points as applied by rollers 143 (FIG. 13), or both,in mutually supporting relationship, or they are fed into or picked upin clips of the shape and form shown in FIGS. 1 and 2, for shipment anduse in a gun magazine of like shape.

NAIL CLIPS Clips of nails collated in two rows of alternating heads andinterdigitated shanks as shown and described are particularly durable.Any group of five nails, as may be marked by A, B, C, D and E forexplanation purposes, present unusual geometrically strong arrangementsin which three heads A, B and E are each in contact with both of theother two; any one head E is contacted by the other four heads A, B, Cand D; and, their shanks form a line of contacting shanks. Thereby eachnail of any three nails contact an adjacent nail at least at two spacedpoints of its length for bilateral support and the strength of thegroup, and, each group of five has at least seven head contacts and fourshank contacts for stability. Moreover, the contact points of the shankscan reasonably be located anywhere within the lower half of the shanks,preferably near the point as at 118 whereby three-point support for eachnail is provided for position strength in the clip and with minimum useof adhesive in a stick, if used.

If an adhesive means 120 is employed to provide nail sticks, it can be anarrow strip along either side or both, of the nail shanks where theycontact as at 118, and along the wave-like interstice occurringcentrally between the two rows of heads as indicated at 122. Whenever itis used quantities required are small and such is shed when the nail isdriven into the wood.

In both instances, the lines of contacts are normal to the nails as thusoriented and collated. For that reason they are mutually well supported.Furthermore, with both columns of loose nails or any sticks of adherednails they can be fed horizontally to the driving chamber of the gun assupported in a gun magazine that in turn squares the nails to the planeof the work surface.

Any clip-like means 21 that supports a group of nails thus collated maybe molded or fashioned of any suitable material such as metal or plasticto define at least two facing channels 124 to support the heads andpreferably a stabilizing channel 126 for the nail points. As shown, theclip comprises two parallel channels forming lower rails 128 externallyand upper walls but inwardly opening towards each other to receive theopposite edges 132 of the collated nail heads and confine them tolongitudinal movement therein. The two channels 124 preferablyconstitute formed edges of a sheet that is substantially V-shaped havingsides 119 to protect the nails against lateral blows and strains duringhandling and also in the gun or during shipping. The angle of the\/-shape sides holds the points of the collated nail heads against thenail heads being cocked or slipping into overlapping relationship.

The clip can be bi-terminal for receiving and discharging the nailsthrough either end. For this purpose both ends are cross-apertured as at145 (FIG. 21) through the sides 119 to receive a nail or bent wire 147therethrough at one or both ends. Preferably, however, at one end a cap149 is provided (FIG. 29) which has its side flanges 151 dimpled at 153to snap in the holes 145 and carries a rod-like spacer 155 (FIGS. 22 and29) that runs the length of the clip 21 in position to engage the nailshanks and hold the heads in place in channels 124 against possibleviolent handling.

NAIL FEED in NAIL GUN Forward feed of the nails to the driving positionis accomplished by a manually adjusted follower 140 (FIG. 21) engagingthe rearmost nail c in the clip for resiliently advancing the nails as agroup.

For receiving a clip or stick to feed nails to their drive position, thegun is provided with an elongated chute or receiver 140 opening into thebarrel 101 and the receiver is provided with parallel facing channels157 that receive the rails 142 of the clip 21 in guided relationship.Also inwardly thereof the receiver has shoulder lands 144 (FIG. 22) thatengage the heads of the nails as at 146 in a slidably guidedrelationship along the top. This relation enables either the use of theclip 21 throughout the driving of the nails therein, or, the clip can beinserted to locate the nails in place, even though loosely collated, andthe clip when withdrawn leaving the nails in feed position in the chute140.

In either event, for resiliently advancing the nails by the follower140, a slot 148 is provided longitudinally in the top wall of thereceiver between the shoulder lands 144 to receive a flexible band orcable 150 that is attached at one end to a spring rotated wind-up drumassembly 152 (FIG. 14) carried by the gun. At the other end the cable150 is secured to an ear 158 on the follower 140. The follower and cableare releasably received in the slot 148 in guided relation to engage therear edges of the tail-end nail heads in the magazine, as at 152. Forthis purpose the follower 140 is constructed to clear the upper edge ofthe cap and operate as a miniature walking beam having cross-arms 154with their forward faces engaging the flat portions on the rearmost nailheads at approximately a spaced distance coincident with the transversespacing of the two rows of shanks.

A handle 156 is carried by the follower 140 for manipulation thereof andextends through the slot 148 and laterally for finger engagement so thatthe follower can be backed out of the slot and reinserted each time themagazine is replenished with collated nails. Furthermore, although thelower outside edge of the magazine can have any exterior designtreatment desired, as at 158, for work engagement, the inside isconformed to guide the collated nail points, thereby making it possibleto use a very thin metal or plastic clip for the nails, which are easilyfilled, emptied, or, serve only as a onetime or repeat use package.

When replenishing the receiver, the follower 140 can be temporarilysupported out of line with the receiver opening to free one of the handsof the operator for replenishing the receiver. Also the handle tracksthe nail supply and serves as a visual indicator of the number of nailsremaining in the magazine.

Although cohesives can be dispensed with in order to save time, moneyand eliminate waste, yet the description will indicate how frangiblecohesives 118 can be employed to make nail sticks, if desired. However,coatings, adhesives and surface etching cannot equal the holding powerof the 12 gauge nail described, but rather detract from it. It is forthat reason that the nails embodying the invention are preferablyhandled without any adhesives on the shanks and adhesives that may beused on the heads will break free on spiral nails so that embedding thehead locks it in wood fibers as noted.

What is claimed is:

1. In a power nailer a housing forming a barrel, a driver reciprocablein said barrel, a reciprocable piston means for actuating said driver tonormally support the lower end thereof at a predetermined level, nailhead locating stop means on opposite sides of said driver below saidpredetermined level, a magazine defining a V-shaped slideway having aportal into said barrel and provided with parallel facing channelsspaced a distance of approximately two diameters of a nail head forsupporting the remote edges of a pair of side-by-side nails offsetlongitudinally of said channels a distance approximately the diameter ofthe shank of said nail, the offset nail heads successively engaging saidstop means on opposite sides of and below said driver.

2. The power nailer defined in claim 1 in which said magazine has alongitudinal slot, and including a resiliently urged retractiblefollower slidable in said slot to move said nail heads into contact withsaid stops.

3. A power nailer comprising,

a housing having a hollow handle defining a compressed fluid reservoir,

a cylindrical sleeve secured within the housing having an enlarged upperportion at one end defining a power piston cylinder, and a lower reducedcylindrical portion therebelow,

a piston reciprocable in said lower cylindrical portion and having anenlarged head portion reciprocable in said upper portion,

said power piston cylinder having ports proximate the upper end andports around the lower end of said enlarged portion,

said housing and sleeve defining a first passageway in communicationwith said upper ports and a second passageway in communication with saidlower ports,

a head closing the upper open end of said cylindrical sleeve and havinga third passage therethrough in communication with said firstpassageway,

said housing having a bore between said passages and said reservoir,

valve means in said bore movable between two positions in one of whichthe first and third passageways are connected to the reservoir and thesecond passageway is vented to atmosphere and in the other one of whichthe first and third passages are vented to atmosphere and the secondpassage is connected to the reservoir,

said piston head portion closing said upper ports in itsrestingposition.

4. The nail driver defined in claim 3 in which said valve means includesa spool valve having ends of different sizes and a sleeve reducing thesize of a portion of said bore adjacent one end to provide adifferential of cylinder sizes at opposite end portions receiving saidheads by which pressure present in the central portion of the spoolvalve urges it to its closed position.

5. The nail driver defined in claim 4 in which said head is removablefor the installation and servicing of said piston and valve.

1. In a power nailer a housing forming a barrel, a driver reciprocable in said barrel, a reciprocable piston means for actuating said driver to normally support the lower end thereof at a predetermined level, nail head locating stop means on opposite sides of said driver below said predetermined level, a magazine defining a V-shaped slideway having a portal into said barrel and provided with parallel facing channels spaced a distance of approximately two diameters of a nail head for supporting the remote edges of a pair of side-by-side nails offset longitudinally of said channels a distance approximately the diameter of the shank of said nail, the offset nail heads successively engaging said stop means on opposite sides of and below said driver.
 2. The power nailer defined in claim 1 in which said magazine has a longitudinal slot, and including a resiliently urged retractible follower slidable in said slot to move said nail heads into contact with said stops.
 3. A power nailer comprising, a housing having a hollow handle defining a compressed fluid reservoir, a cylindrical sleeve secured within the housing having an enlarged upper portion at one end defining a power piston cylinder, and a lower reduced cylindrical portion therebelow, a piston reciprocable in said lower cylindrical portion and having an enlarged head portion reciprocable in said upper portion, said power piston cylinder having ports proximate the upper end and ports around the lower end of said enlarged portion, said housing and sleeve defining a first passageway in communication with said upper ports and a second passageway in communication with said lower ports, a head closing the upper open end of said cylindrical sleeve and having a third passage therethrough in communication with said first passageway, said housing having a bore between said passages and said reservoir, valve means in said bore movable between two positions in one of which the first and third passageways are connected to the reservoir and the second passageway is vented to atmosphere and in the other one of which the first and third passages are vented to atmosphere and the second passage is connected to the reservoir, said piston head portion closing said upper ports in its resting position.
 4. The nail driver defined in claim 3 in which said valve means includes a spool valve having ends of different sizes and a sleeve reducing the size of a portion of said bore adjacent one end to provide a differential of cylinder sizes at opposite end portions receiving said heads by which pressure present in the central portion of the spool valve urges it to its closed position.
 5. The nail driver defined in claim 4 in which said head is removable for the installation and servicing of said piston and valve. 